In the 3GPP, a framework for distributing a warning message to a specific distribution area on a packet switching network (hereinafter referred to as a warning distribution system) is specified.
Referring to FIG. 6, the operation of such a warning message distribution system is described.
As shown in FIG. 6, in step S2001, a flash report transmission station CBE transmits, to a message distribution station CBC, a message distribution request for requesting distribution of a warning message.
In step S2002, the message distribution station CBC determines one or multiple tracking areas (TA), and distribution area information (Warning Area ID), based on distribution target area information contained in the message distribution request.
In step S2003, the message distribution station CBC transmits, to a mobile control apparatus MME corresponding to each tracking area, a message distribution request including the above-mentioned tracking areas and distribution area information.
In step S2004, the mobile control apparatus MME identifies the radio base station eNB belonging to each tracking area contained in the received message distribution request.
In step S2005, the mobile control apparatus MME transmits, to the identified radio base station eNB, a message distribution request including the distribution area information.
In step S2006, the radio base station eNB determines whether the radio base station eNB itself is included in the distribution area for the warning message based on the distribution area information contained in the received message distribution request.
When determining to be included in the distribution area for the warning message, the radio base station eNB distributes the warning message to the mobile stations in the distribution area corresponding to the distribution area information in step S2007, and transmits a warning message transmission acknowledgement which indicates the distribution to the mobile control apparatus MME in step S2008.
In step S2009, the mobile control apparatus MME transfers the warning message transmission acknowledgement received from the radio base station eNB to the message distribution station CBC.